Introduction

Offences under the Ancient Monuments and Archaeological Areas Act 1979 occupy a distinctive area of criminal law. They are neither conventional planning breaches nor straightforward criminal damage cases. Instead, they form a specialist statutory regime designed to protect scheduled monuments and heritage assets, with potentially serious financial and custodial consequences.

This article explains the structure of the main offences under the 1979 Act, including unauthorised works, damage to protected monuments and metal detecting offences, together with available defences and the approach to sentencing.

As a practitioner in this area, it has always struck me that this offences sit in an unusual space. They are neither conventional planning offences under the Town and Country Planning Act 1990 , nor are they simply a specialist subset of the common criminal offence of criminal damage. 

The Ancient Monuments and Archaeological Areas Act 1979 creates a dedicated criminal regime designed to protect important archaeology and historic fabric. This is through the mechanism of scheduling, it works via restrictions on intrusive activity such as unauthorised works and metal detecting. 

The result is a set of offences that can be prosecuted even where the physical harm is not dramatic in ordinary property terms, because the statutory focus is on harm to the heritage asset and the public interest in its protection.

The main offences

Ancient Monuments and Archaeological Areas Act 1979 Act deliberately separates three kinds of wrongdoing: 

i)    proceeding without consent (section 2), 
ii)    causing actual harm with a culpable mental state (section 28), and 
iii)    intrusive searching and removal behaviour associated with looting (section 42). 

Each of these offences has its own elements and statutory defences but taken together, they provide a coherent statutory scheme for protecting scheduled monuments and heritage assets.

What is a scheduled monument?

The core concept within the 1979 Act is what is called a ‘scheduled monument’. Section 1 requires the compilation and maintenance of a schedule of monuments. Once a monument is scheduled then section 2 imposes a control regime over works which may affect it.  

Section 28 creates a separate offence of destroying or damaging a protected monument without lawful excuse. The Act also creates restrictions on the use of metal detectors in ‘protected places’, which include scheduled monuments and certain other protected land.

Unauthorised works contrary to section 2 Ancient Monuments and Archaeological Areas Act 1979

Section 2 of the 1979 Act criminalises executing, causing, or permitting to be executed any works to which the section applies unless Scheduled Monument Consent has been granted and the works are carried out in accordance with that consent. 

The breadth of what we lawyer call secondary liability (causes or permits) really matters in practice, because it means that prosecutions can be brought not only against the person whop actually physically does the work but also against owners, developers, contractors, or project managers who have authorised, enabled, or turned a blind eye to works that require consent.

The ‘works’ that trigger the offence are defined expansively. They include works resulting in demolition or destruction of, or damage to, a scheduled monument; works for the purpose of removing or repairing a scheduled monument or any part of it; works for making alterations or additions; and (critically in rural cases) flooding or tipping operations in, on or under land where there is a scheduled monument. 

Deliberately wide definitions captures activity that may be presented as routine land management but which is capable of disturbing archaeological remains.

The elements of the offence- s2 Ancient Monuments and Archaeological Areas Act 1979.

To prove the offence, the prosecution must prove, beyond reasonable doubt that: 

i)     the monument was scheduled, 
ii)    the defendant executed, caused, or permitted qualifying works, and 
iii)    consent had not been granted or that the works were not in accordance with the consent. 

The key issue in consideration of a s2 offence is usually whether what was done falls constitutes works, and whether the relevant defendant can properly be said to have caused or permitted it.

Defences to prosecutions under s2 Ancient Monuments and Archaeological Areas Act 1979. 

Defences are very fact specific and there are no blanket rules but there are some common defences which can be successfully employed.  

The Act provides a defence where the accused can prove that they took all reasonable steps to find out whether there was a scheduled monument within the area affected and did not know, and had no reason to believe, that the monument was within that area or that it was a scheduled monument. 

This is not likely to succeed if it is a mere plea of ignorance but it is in effect a due diligence defence that relies on reasonable steps being taken and the state of the accused’s mind based on what they did. 

Where a prosecution is for breach of a condition attached to consent, the Act provides a defence if the accused proves that they took all reasonable precautions and exercised all due diligence to avoid contravening the condition. 

There is a further defence where the works were urgently necessary in the interests of safety or health, though the statutory language and application are fact-sensitive and the defence should not be treated as a general “emergency” excuse for convenience works.

Sentencing for section 2 Ancient Monuments and Archaeological Areas Act 1979 

The penalties for section 2 permits serious outcomes. The offence is triable either way meaning that it can be tried in the Magistrates Court or Crown Court and conviction in either court can result in the maximum of an unlimited financial penalty, reflecting the often significant public interest in deterrence and remediation.

Destroying or damaging a protected monument: section 28 Ancient Monuments and Archaeological Areas Act 1979

Section 28 is conceptually closer to criminal damage, but it is a distinct offence targeted at “protected monuments”. It criminalises, without lawful excuse, destroying or damaging a protected monument. Unlike section 2, the offence is explicitly framed by a mental element of intention or recklessness in relation to destruction or damage. The definition of protected monument includes scheduled monuments and certain monuments in public ownership or guardianship under the Act.

The elements of the offence of destroying or damaging a protected monument

The prosecution must therefore prove, to the criminal standard:

i)    that the there is a protected monument, 
ii)    That it was destroyed or damaged, 
iii)    The defendant’s intention or recklessness as to that destruction or damage, and 
iv)    absence of lawful excuse. 

Sentencing for the offence of destroying or damaging a protected monument:

Section 28 carries heavier custodial exposure than section 2. It provides for imprisonment up to two years on indictment, or a fine, or both. 

Metal detecting and removal: section 42 Ancient Monuments and Archaeological Areas Act 1979.

Section 42 addresses unauthorised detecting and the removal of objects discovered by metal detecting. 

The section makes it an offence to use a metal detector in a protected place without written consent, and separately criminalises the removal of an object of archaeological or historical interest discovered by the use of a metal detector in a protected place without written consent. 

The term ‘protected place’ includes scheduled monuments and other protected sites.

Section 42 Metal detecting defences

Section 42 contains a statutory defence that in proceedings for the use offence, it is a defence for the accused to prove that the metal detector was used for a purpose other than detecting or locating objects of archaeological or historical interest. 

In practice this is an evidentially demanding defence when the evidence points to searching behaviour. It should also be noted that ‘metal detector’ is defined widely enough to catch some survey equipment, and that the statute recognises that not every use in a protected place is hunting for historical artefacts.

Enforcement in practice and sentencing approach

Reported appellate case law on prosecutions under the 1979 Act is relatively sparse, in part because many prosecutions are dealt with in the Magistrates Court or result in unreported Crown Court outcomes. 

Historic England has publicised convictions and substantial financial orders following which demonstrate that the financial consequences upon conviction can be significant even where the immediate actor is not a commercial developer.

There are no Sentencing guidelines for 1979 Act offences in the way there is for, say, general criminal damage or theft, but sentence is usually guided by issues such as 

-    the seriousness of heritage harm, 
-    remediation needs, 
-    culpability (including planning, concealment, persistence, or profit motive), 
-    the impact on irreplaceable historic fabric. 

Historic England has published detailed guidance for sentencers on heritage crime which is often used in practice to articulate harm and the public interest in deterrence, including the utility of heritage crime impact statements to assist the court. You should seek specialist legal advice if seeking to interpret where a specific offence falls under the guidelines. 

Conclusion

In conclusion, offences under the Ancient Monuments and Archaeological Areas Act 1979 is a regime that is substantively distinct from most areas of planning and criminal law. 

The statutory scheme turns on precise definitions, carefully framed mental elements and due diligence defences, and on a consent system that can render otherwise ordinary land use criminal. 

The relative scarcity of reported appellate authority means that much turns on close analysis of the legislation, the facts, and the approach of specialist prosecuting bodies. 
The consequences of falling foul of the law can be serious, including substantial financial penalties and, in some cases, custodial sentences. 

It follows that this is an area where early, informed legal advice is often critical, both to navigate the consent regime lawfully and to manage risk if enforcement action is threatened or commenced.

Quentin Hunt is a criminal defence barrister who specialises in defending in planning and heritage prosecutions. He accepts instructions either through solicitors or directly from members of the public or companies.

If you have a concern over any of the above issues or face investigation or prosecution then you may contact Quentin for a free, no obligation conversation about how he could help in your case.